Combined telephone and telegraph system



0d. 27, 1931. E. R. TAYLOR COMBINED TELEPHONE AND TELEGRAPH svsma Filed March 18. 1930 MME-MIN INVENTOR We. ATTORNEY `graph apparatus patented Oct. 27, QS

PATENT `yo'FFiCr.

UNITED s'rfxriisA EDMUND R. TAYLOR, F NEW YORK, iN. Y., ASSIG'NOR T0 AMERICAN TELEPHONE AN TELEGRLAPH COMPANY, A CORPORATION OF NEVI YORK f COMBINED TELEPHONE AND `Tui.irri-nains SYSTEM Appiicauon inea Maren is, iaeo. 'seriaino. 436,796.

This invention relates to combined telephone and telegraph systems andparticularly to arrangementsl for switching teleinto association Ywith the telephone circuit when it is not being used ytor telephone transmission.

Four-wire telephone systems are usually provid-ed with voice-operated arrangements for suppressing echoes and preventing singing over the four-wire circuit.' In a well Kknown arrangement of thistype voice-'operated relays are provided whereby' when transmission takes place from the two-wire Vterminal out over the transmitting side of the four-wire circuit, the normally disabled transmitting channel will be cut through for ftransmission and the receiving circuit will at the same time'be disabled. Similarly,

when telephone transmission is being received over the receiving side of the circuit, voice-operated relays will disable the transmitting side as well as the voice-operated equipment associated therewith rto prevent "any interference with reception.

TWhen such a circuit is to be used Afor full duplex telegraph transmission, if the telegraph transmitter is to be applied to the twowiie terminal it is obviously necessary to actuate the voice-operated relays which cut through the transmitting side of the circuit. This may be done automatically upon the connection of the telegraph transmitter to Vthe circuit but necessarily results in disabling the receiving side of the circuit at the saine4 time. must be associated with the receiving side of Therefore, the telegraph receiver the four-wire circuit beyond the point at which it is disabled 'in order that telegraph signals may be freely received.

Where several four-wire circuits are provided and one or more telegraph sets are available, the present invention provides an `arrangement whereby when the transmitring apparatus of a telegraph set ris connected to the two-wire terminal of a particular four-wire circuit, its corresponding telegraph receiving apparatus is automatically vswitched into lconnection with the receiving side of the four-wire circuit.

The invention will now be more fully understood from the ollowing description when read in connection with the accompanying drawing, the figure of which illustrates in schen'iatio iorm the preferred embodiment of the invention. y Y

Reerring to the drawing, the terminal arrangement of a tour-wire system comprisp ing atransmitting line yTL and a receiving Vline RL is illustrated. 'i 1n practice the transmitting'line may be associated with the radio transmitter of a transatlantic telephone circuit, and the receiving'line with the correspending radio receiver' of suoli a system. The ends of said lines are connected through it'act koit-a voice-operated relay TVR. This relay may be operated by l'currents from an ainpliier-detector arrangement TV yassociated .with the transmitting line TL so when 4voice currents flow over vsaid linev the vnormal short-,circuit controlled by the relay TVR will be opened to cut the line through for transmission.- At the same time another 'Contact of Vthe 'relay TVR is closed to disable tl'ie receiving line RL. 'A delay circuit TDN. maybe provided betweenthe ampli- -ier-det'ector arrangement `TV and the point at which'the short-circuit is applied to the line TL in order to enable the relay TV R to operate before the voice currents arrive at V*the short-circuit.V l ,v With the relay TVR operated, transmission may take place from the two-wire ter.- ininal overthe transmitting line lTL/but currents cannotl be transmitted from the receiving line RL to the ytwo-wire terminal. In order that transmission may takeplace in the opposite direction, an amplifier-detector l RV is associated with the lreceiving line RL and controls the rrelay RVR which, when actuated, closes a .short-circuit across the Atransmittingline TL, this short-circuit at the lsame time disablingy thel amplifier-detector TV and preventing any interference with reception f over the line `It will thus be seen that transmission may take place in only one direction at a time.

The telephone system above described may be used for telegraph transmission when it is not' being employed for telephony and preferably the telegraph signals would be transmitted and received as audible tones modulated or controlled in accordance with the telegraph message. Vhen a telegraph transmitter is connected to the two-Wire terminal of the jack J, it is obviously necessary to actuate the relay TVR to remove the short-circuit from the transmitting line TL. This results in disabling the receiving line RL at the same time by means of the inner contact of the relay TVR. Consequently, it has been the practice heretofore to permanently connect the receiving telegraph apparatus With the receiving line RL at a point beyond the short circuit controlled by the relay TVR.

Vhere a number of such telephone circuits are provided and one or more sets of telegraph equipment are available, an arrangement such as above described becomes im- .practicable as flexibility in the connection of the telegraph equipment to the idle telephone lines is impossible. To avoid this difficulty the present invention provides an arrangement whereby when a telegraph transmitter is connected to the tivo-Wire terminal at ack VJ, the corresponding telegraph receiver Will be automatically associated With the receiving line RL.

In the drawing the telegraph transmitting equipment is shown as comprising a trans Ymitting printer TP which sends direct cur- YP of a cord circuit C in the jack J of the two-Wire terminal of the telephone circuit and in the jack J of the telegraph transmitter, respectively. When this connection is established the circuit of relay F associated With the telegraph transmitter, and of relayY TG associated With the tivowvay telephone terminal Will be completed from battery over the tip contact of the jack J, tip contact of the plug P, tip conductor of the cord C, tip contacts of the plug P and jack J, through the Winding of the relay TG, over the ring contacts of the jackJ andplug P, ring conductor of the cord C, ring contacts VWith the receiving line vleased* at the same time, thereby causing` the of the plugs P and jack J and thence through the Winding of relay F to ground.

W hen the relay F is energized it closes the circuit of the relay Z which removes ground from the test contact corresponding to the connected telegraph apparatus at each of the selective switches that are associated with the several telephone circuits. The energi- Zation of the relay TG connects ground to the voice-operatedrelay lTVR and causes said relay to disable the receiving line RL and at the same time remove the normal short-circuit -from the transmitting line TL. The system is now in condition to transmit telegraph signals from the printer TP over the cord circuit G and 'thence over the transmitting line TL.

The operation of the relay TG also completes the circuit of relay P which in @urn completes circ i'rom battery over the contact of said relay, normal inner right hand Contact relay X, through :he stepping magnet Siri oi' the selective switch associated with the telephone line, through the interrupting contact of said magnet, and thence over wiper a to ground over the test contact ot'l the selector bank. Tl completion ot' this circuit causes lil@ the stepping magnet SM to automatically ad- Vance the Wip rs step by step until the wiper a. encounters the Contact iroin which ground was removed by the operation ci? the relay `.uring this operation the i' 'lit-hand winding of relay X has been short-circuited by the ground connected to the i per a, but as soon as the Wiper encounters an open circuit vthis short-circuit is removed andthe right-hand 4Winding of relay X is energized in series With thestepping magnet fili/l as soon as the latter releases its armature. The relay X upon being energized, at its inner right-hand contact opens the circuit of the stepping magnet SM and locks up Vover its left-hand .vinding and the lcontact of the relay P. Relay X at its outer right-hand Contact completes the, circuit of relay Y which in turn connects ground to the test -Wiper u to prevent any other switches associated with other telephone circuits from selecting the telegraph receiving eipiipment Which is now associated iii over tho Wipers 7) and c ot' the selecting switch and over the leict-hand front contacts of the relay X. Telefaph transmission may now take place over the circuit in both directions simultaneously.

lVhen it is again desired to use the telephone circuit Jfor telephone transmission the plugs P and P are Withdrawn. tl'xereby rcleasing relays TG and F. Relay F releases relay Z which again connects ground to the test contact oit the selector switch. Relay TG in turn releases the relay TVR to restore the telephone circuit to normal. Relay P is rearmatures of relays X and Y to fallibac'lr 130 and restore the circuit to normal. The deenergization of relay X disconnects the receiving line RL from the telegraph receiving equipment at the left-hand contacts of said relay although said telegraph receiving selector svvitcli.

GLS

lt will be obvious that the general principles herein disclosed may be embodied in many oiher organizations Widely different from those illustrated Without departing from the spirit of the invention as defined in the following claims.

W'hat is claimed is rl. In a transmission system, a -four-Wire telephone circuit comprising a transmitting line and a receiving line connected to a tvvo- Wire terminal, a telegraph apparatus comprising a telegraph transmitter and a 'telegraph receiver, means to connect the telegraph transmitter to the tivo-Wire terminal of the telephone circuit at the will of the operator, and

means automatically responding to such con-V nection to connect the telegraph receiver to the receiving side of the four-Wire circuit.``

2. lin a transmission system, a plurality of four-Wire telephone circuits each comprising a transmitting line and a receiving line connected to a tivo-Wire terminal, telegraph apparatus comprising a telegraph transmitter and a telegraph receiver, means to connect the telegraph transmitter to the tvvo-vvire terminal of any one of said telephone circuits, and means associated with the receiving line of each telephone circuit to automatically select the telegraphy receiver in response to the connection of the telegraph transmitter to the tivo-Wire terminal of the telephone circuit.

3. In a transmission system, a plurality of four-Wire telephone circuits each comprising a transmitting line and a receiving line con-V nected to a two-Wire terminal, telegraph apparatus comprising a telegraph transmitter and a telegraph receiver, meansto connect the telegraph transmitter to the tWo-Wire tei'- miiial of any one of said telephone circuits, and a step-by-step switch associated With the receiving line of each four-Wire telegraph circuit to select the telegraph receiver in response to the connection of the telegraph transmitter to the two-Wire terminal or said telephone circuit.

el. In a. transmission. system, a four-Wire ,circuitY comprising a transmitting line rand a receiving line connected to a two-Wire termiterminal to remove thedisabling means from the transmitting line andi to Adisable the receivinggline, a telegraph apparatus comprisj ing aJtelegraph transmitterzand a telegraph i receiver, means to connect/the telegraph vtransmitter =to the two-Wire terminal ofthe telephone circuit,fmeans responsive to such connection to cause the voice-operatedappa- -ratus lassociated Withy the transmitting line to 'cut through the transmitting line for transmission and disable the receiving line, and.

lmeans responsive to the connection oi" the L. Q v Y. Y Y L telegraph transmitter to the two-Wire termi- 'nal' to automatically connect the vtelegraph receiver tothe receiving line oic the-telephone ycircuit, beyond the point at which it isl disabled.

y5. In altransmission system, a'pluralit'y of n four-Wire telephone circuits each comprising f a transmitting line and a receiving line connected to a two-Wire terminal,l the transmitting line of each four-Wire circuit being normally disabled, voice-operatedapparatus associatedvvith each transmitting line and re-l sponsiveV to transmission trom the two-Wire terminal to remove the disabling means from each transmitting line and Qdisable the corresponding receiving line, a telegraph apparatus comprising a telegraph transmitter and a telegraphreceiver, means to connect-the telegraph transmitter to the tvvo-vvire terminal of any four-Wire circuit, means responsive to suchy connection to operate thevoice-operated apparatus associated with the corresponding transmitting line to remove the disabling` means therefrom and to disable the corresponding 'receiving line, and means assoy ciated With the receiving line of each four- Wire circuit for automatically selecting the telegraph receiver and connecting it to the receiving line at a point beyond Which itis disabled, said selecting means acting in response to the connection of the telegraph transmitter to the corresponding two-Wire terminal.

6. In a transmission system, a plurality of four-Wire telephone circuits each comprising a transmitting line and a receiving line connected to a two-Wire terminal, the transmitting line of each four-Wire circuit being normally disabled, voice-operated apparatus associated With each transmitting lineand responsive to transmission from the two-Wire terminal to remove the disabling means from` each transmitting line and disable the corresponding receiving line, a telegraph apparatus comprising a telegraph transmitter and a telegraph receiver, means to connect the telegraph transmitter to the two-Wire terminal of i .any fourfwire circuit, means responsive to such connection to operate the voice-operated apparatus associated With the corresponding transmitting line to remove the disabling means therefrom and to disable the corresponding receiving line, and a step-by-step selector associated -vvitli the receiving line of each fourWire circuit and operating inresponse to the connection of the telegraph transmitter to the two-Wire terminal of any telephone circuit to select the telegraph receiver and connect it to the corresponding receiving line beyond the point at which it is disabled.

7. In a transmission system, a plurality of four-Wire telephone circuits each comprising a transmitting line and a receiving line connected to a two-Wire terminaba plurality of telegraph sets each comprising a telegraph transmitter and a telegraph receiver, means to connect the telegraph transmitter of a set to the tWo-Wire terminal of any one of said telephone circuits, and means associated with .the receiving line of each telephonecircuit to automatically select the corresponding telegraph receiver of a set in response to the connection of the telegraph transmitter thereof to the two-Wire terminal of the telephone circuit.

In testimony whereof I have signed my name to this specification this 17th day of March, 1930.

, EDMUND R, TAYLOR.

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